Just a random thought on meadows versus pastures: from my memory of living adjacent to farmland (at least way out here in the wild wesht), a field could be either depending on the time of year and the farmer's requirements. I'm not convinced it's an entirely valid distinction. The term "grassland" strikes me as a broadly useful one.
On Wed, 2011-02-09 at 23:12 +0000, John Kennedy wrote: > Following up... I was not clear but of course I wouldn't like us to lose the > detail provided by Corine. I guess we and UK have more pasture than mainland > Europe and Corine has not been added to UK yet so perhaps this is first time > the subtlety of significant amount of farmland being under grass has arisen. > > To summarise my understanding the farmland options seem to be > 1 - bend/interpret the OSM wiki definition of meadow to include farmed land > under grass for now - could potentially bulk re-tag corine meadows in the > future? > 2 - propose the OSM wiki definition of meadow be changed to include farmed > land under grass > 3 - propose qualifications for landuse=farm (e.g. farm=tillage, > farm=grassland) so at least arble land and farmland under grass can be > differentiated and rendered differently. The term "grassland" seems to be an > acceptable term (e.g. by BTO, CBS) to describe a grassy field that may be > grazed by animals, harvested as hay, or harvested as silage. The term > 'pasture' might imply presence of animals to some people so I would suggest > we avoid that term. With this option, option 3, the landuse=meadow could > remain as is in OSM wiki definition, i.e. relatively natural grassy land > that is not part of a farm (if I read it correctly). > 4 - ?? > > I'm still relatively new to all this. My gut tell's me 3 is the ideal way > forward but I have no idea of timelines and implications. > > Re bogs, thinking about it actually the experts in Ireland are the IPCC. > This page is interesting: http://www.ipcc.ie/bogsform.html. > > It suggests this hierarchy: > (landuse?)=peatland > peatland = fen or bog > bog = blanket or raised > blanket = mountain or Atlantic (if we want to go the whole hog. > > Re harvesting I agree that is worth capturing too. IPCC have this page: > http://www.ipcc.ie/cbdefinition.html. It seems bog with industrial scale > harvesting is called "cutaway". The term "cutover" is used for smaller scale > / manual harvesting. I don't know the best way of assigning attributes to a > tag perhaps someone else can suggest that. > > The IPCC have probably already cataloged or even mapped which bogs are which > - maybe even boundaries. I live in their part of the world and could make > some enquiries. They could also clarify if the above proposals are sensible > from their perspective and if the terminology is internationally recognised > and comprehensive. > > HTH, > - John > > > > > On 9 February 2011 14:13, John Kennedy <[email protected]> wrote: > > > Thanks for the clarifications. Glad I asked re the estates - makes sense > > and will save me some work. > > > > Re farm just to point out I based my observation on turning meadow into > > farm based on the definitions on OSM. They imply to me that 'meadow' is for > > land that is not being farmed. Farm explicitly includes both tillage and > > pasture. > > > > http://wiki.openstreetmap.org/wiki/Tag:landuse%3Dfarm > > http://wiki.openstreetmap.org/wiki/Tag:landuse%3Dmeadow > > Some discussion: > > http://wiki.openstreetmap.org/wiki/Talk:Tag:landuse%3Dfarm > > > > One possibility that avoids changing the OSM wiki definition of meadow/farm > > - is it worth proposing qualifications for landuse=farm? e.g. > > farm=tillage > > farm=pasture > > > > Opening up landuse discussion to bogs too, FYI here is a classification > > used in national scientifically rigorous wildlife surveys in Ireland: > > http://www.birdwatchireland.ie/Portals/0/images_large/CBS_habitatguide.jpg > > > > [Full credit: the BTO developed this hierarchy. E.g. > > http://www.sorby.org.uk/recording/bird-habs.shtml] > > > > I do not propose that we use all of the level 2's, but it might raise > > subtleties that would be useful to capture. > > > > Food for thought. > > - John > > > > > > > > On 9 February 2011 01:24, Dermot McNally <[email protected]> wrote: > > > >> Hi John, > >> > >> On 9 February 2011 00:47, John Kennedy <[email protected]> wrote: > >> > >> > I never used polygons before but I think I have got my head around it on > >> the > >> > dev box - thanks for setting it up. Will know for sure when I start > >> seeing > >> > updates after it goes live. I must admit I found some of the polygon > >> > highlighting inside JOSM counter-intuitive. e.g. When I highlighted a > >> meadow > >> > outer, it highlighted the area outside the meadow rather than inside it. > >> > This might be related to the large meadow that was split. > >> > >> Probably this is because you were selecting part of a relation not all > >> of whose member elements had been downloaded. As you say, this is > >> particularly likely for large polygons. JOSM has an option inside the > >> relation edit dialogue to have it download any missing elements - it > >> looks a bit like the normal download toolbar button, and you'll > >> probably find that the highlighting will fix itself up once you do > >> this (but only for the relation in question, so it's often quicker > >> just to download a bigger buffer around your editing area). > >> > >> > The difference between farm and meadow seems arbitrary where I checked - > >> > browsing osm wiki I guess most meadow will turn into farm - but if there > >> is > >> > Irish preference to e.g. tag pasture as meadow pls advise. > >> > >> I've already mentioned that we may need a consensus on bog, and it > >> looks a lot like farmland will need the same thing. If there is a > >> sufficient consensus that Corine pastures should not map to OSM > >> meadows then we have the option of regenerating the import data set > >> with whatever different tagging proves most popular. > >> > >> But understand that Corine has a few different agricultural land cover > >> types, of which the most common ones in Ireland seem to be arable and > >> pasture. So far I have been mapping arable to farm and pasture to > >> meadow. This is what has been done in at least some of the other > >> countries to perform a Corine import. It has the IMO important effect > >> of retaining the knowledge that the two uses are different, though I > >> note your point that the difference may seem arbitrary - keep in mind > >> that this might be due to the fact that many Irish farms are > >> sufficiently mixed for the Corine surveyors to have to choose one of > >> the two classifications for the entire area. In such cases, the real > >> fix is to map the reality at a more detailed level, not to assume that > >> the differentiation has no value. > >> > >> As a non-farmer with _some_ awareness of the countryside, I'll outline > >> my gut definitions of the words in question: > >> > >> Arable: Tillage, the growing of any crop. The brown rendering of the > >> OSM farm type seems to suit this > >> Pasture: An area under grass for grazing by animals. Seems to merit > >> green rendering but may not be a good fit for OSM meadows > >> Meadow: An area under grass, ungrazed, to be cut for hay. Seems to > >> merit green rendering and to match well to OSM meadows > >> > >> What is interesting is that Corine has only a pasture category, but > >> nothing for meadows. One comment I have read on Corine (unrelated to > >> farming) is that it is to capture land cover, not land use. This can > >> be the same - a bog being harvested by Bord na Móna is both a land > >> cover of bog and an industrial use of that bog. But it's not clear > >> that Corine's surveying methods can readily tell the difference > >> between areas under grass, nor that they particularly care about the > >> difference. > >> > >> Richard Canwell, who is on this list, may be able to clarify this. OSM > >> does have other grass-ish tags, including landuse=grass, so we do have > >> options other than to map Corine pastures to meadows just because > >> others have done so. > >> > >> > I have distinct landuse=residential for each estate I mapped. I just > >> used > >> > simple continuous way areas with adjacent estates almost touching. I > >> might > >> > use this import cleanup as opportunity to go the 'refined' route which > >> if I > >> > understand correctly is: > >> > - create individual ways for each individual border between adjacent > >> areas > >> > - create relation of all ways that make an estate border. > >> > - tag the relation with estate name > >> > If I have misunderstood pls advise. > >> > >> Opinions differ about this. Most Irish mappers dislike the gluing of > >> areas to linear features like roads, but many do find it useful to > >> glue areas together, especially where they have confidence that they > >> will not later wish to map something else in between (this is one of > >> the better reasons for not gluing residential areas to roads - if you > >> later want to map the perimeter fence, where can you put it?) > >> > >> I map residential areas exactly as you have described above, and I > >> think I'll keep doing it this way because it gives me, for instance, > >> the option to later map a belt of trees (which is an area, though a > >> thin one) between adjacent residential areas, as can arise. Even for > >> simpler mapping, the visual separation gained from the hairline > >> between adjacent residential areas is IMHO desirable, as it shows the > >> extent of a named estate. > >> > >> > One last thing, it is a signficant change so would recommend a blast to > >> all > >> > (recent) Irish mappers via internal OSM mail ...just like was done for > >> the > >> > license change...to bring everyone up to speed before the live import. I > >> for > >> > one only came across this list recently. > >> > >> The idea is good, though I'll note that the messages sent regarding > >> the licence were sent manually, something that would be cumbersome on > >> this occasion. Rorym does have, I think, a script that can do the job > >> and has used it before to announce mapping parties, so that option > >> remains open to us. My own feeling is that, if we do it, we should > >> attempt to exclude mapping tourists and low-volume mappers from the > >> notification. The former because the area of imports is rather tainted > >> in many OSM circles and a strong opinion not founded on local > >> community considerations doesn't necessarily get us anywhere. My one > >> concern here is that I'm aware of a very few visitor mappers who have > >> mapped landuse, though even those mappers would probably find it > >> difficult to recall enough to make their cleanup services useful. > >> > >> My reason to exclude low-volume mappers is that there is a seriously > >> long tail of contributions in Ireland. Low-volume mappers often > >> contribute a handful of POIs and/or some road names. Much of our > >> message will go over the heads of such mappers, many of whom are using > >> simply POI-collecting apps and not full editors. > >> > >> Regardless, I think we should learn as much as we can from this thread > >> before going broader, as it will give us a chance to tune our message > >> in a more helpful direction and take some of the techy edge off it. > >> > >> Thanks for the very useful feedback, and please let's have yours and > >> others' suggestions for how to resolve the pasture/meadow issue, > >> Dermot > >> > >> > >> -- > >> -------------------------------------- > >> Igaühel on siin oma laul > >> ja ma oma ei leiagi üles > >> > >> _______________________________________________ > >> Talk-ie mailing list > >> [email protected] > >> http://lists.openstreetmap.org/listinfo/talk-ie > >> > > > > > _______________________________________________ > Talk-ie mailing list > [email protected] > http://lists.openstreetmap.org/listinfo/talk-ie > _______________________________________________ Talk-ie mailing list [email protected] http://lists.openstreetmap.org/listinfo/talk-ie
